and they began to use abstract numbers. previously, a token was impressed once for each measure it represented. 12 impressions meant 12 jars of oil. now, the commodity was drawn once. a jar of oil. tokens symbolized numbers. a sphere meant 10, and a cone meant 1. so on this tablet is recorded 10, 11, 12 jars of oil. the number of graphic symbols was expanded quickly, as scribes sought to express more complex ideas. a star shape, to represent god or heaven. a head plus a bowl, for the verb "to eat." over time, the symbols themselves evolved into the wedge-shaped characters called cuneiform. but the greatest advance came when scribes began to use cuneiform to represent the sounds of spoken sumerian. the word "an" meant "heaven" but was also used to represent the sound "an" in words like "anbar," meaning "iron" and "anta", meaning "above." for the very first time in human history, people could make a permanent record of their spoken language. but sumerian hasn't been spoken since about 2000 b.c. how could these markings be rea